Kamacite, mineral consisting of iron alloyed with 5–7 percent nickel by weight and found in almost all meteorites which contain nickel-iron metal. It has a body-centred cubic structure and is sometimes referred to as α iron, after one of the three temperature-dependent forms (allotropes) of pure iron, because the kamacite has the same body-centred cubic structure as α iron. In the iron meteorites, it comprises all the metal in hexahedrites; it also is a principal constituent of the octahedrites, where it is intergrown with taenite, a face-centred cubic nickel-iron mineral.

Kamacite and taenite.

NASA

Learn More in these related articles:

any fairly small natural object from interplanetary space—i.e., a meteoroid —that survives its passage through Earth’s atmosphere and lands on the surface. In modern usage the term is broadly applied to similar objects that land on the surface of other comparatively large...

any meteorite consisting mainly of iron, usually combined with small amounts of nickel. When such meteorites, often called irons, fall through the atmosphere, they may develop a thin, black crust of iron oxide that quickly weathers to rust. Though iron meteorites constitute only about 5 percent of...

nickel-iron mineral having a face-centred cubic structure and playing a major role in the crystallization and structure of iron meteorite s and stony iron meteorite s. It is sometimes referred to as γ iron, after one of the three temperature-dependent forms (allotropes) of pure iron, because...